1. Field of the Invention
The invention relates to a method of manufacturing an annular skin for foamed product with skin and a method of manufacturing a foamed product using such skin.
2. Description of the Related Art
Some headrests that are mounted on a top of the backrests of seats in automobiles or the like have a hole. Such a headrest with the hole is usually prepared as a foamed product with skin with the middle portion thereof hollowed out so that the back part of the head can rest therein. The entire part of the foamed product is covered with a skin.
A method of manufacturing headrests with the hole of this type involves the steps not only of first preparing a foamed body and then covering a skin over the foamed body, but also of arranging a fastener to the outer periphery. When such a method is employed, the costs of manufacture of the headrests become elevated. Another method of manufacturing headrests with an opening involves skin integrated foaming while using no fastener. However, this method has a difficulty in concealing the outlet seams.
Under such circumstances, e.g., Examined Japanese Patent Publication No. Hei. 4-40181 proposes a method of forming an annular headrest by stitching skin forming pieces one by one.
The art disclosed in the aforementioned publication is characterized as joining the cubic cylindrical opening edges of split pieces of a skin body together and, therefore, this art involves a cumbersome and time-consuming operation. In addition, when the skin forming pieces formed in cylindrical form are joined together from one piece to another, a special sewing machine such as a spot sewing machine must disadvantageously be employed because the diameter of the cylindrical body is small.